--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MetroWpf/MetroWpf.Xaml/Converters/NumberPositiveToNegativeConverter.cs	Mon Mar 12 23:05:21 2012 +0800
@@ -0,0 +1,34 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+namespace MetroWpf.Xaml.Converters
+{
+    public sealed class NumberPositiveToNegativeConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is Byte)
+                return (Byte)((Byte)value * -1);
+            if (value is Int16)
+                return (Int16)((Int16)value * -1);
+            if (value is Int32)
+                return (Int32)value * -1;
+            if (value is Int64)
+                return (Int64)value * -1;
+            if (value is Single)
+                return (Single)value * -1f;
+            if (value is Double)
+                return (Double)value * -1d;
+            if (value is Decimal)
+                return (Decimal)value * -1m;
+            return DependencyProperty.UnsetValue;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return Convert(value, targetType, parameter, culture);
+        }
+    }
+} ;
\ No newline at end of file